Estimation method for greenhouse gas emission of farmland covered by biological plastic film

Abstract

The invention provides a method for estimating the greenhouse gas emission amount of a farmland under biological mulching film coverage, and belongs to the field of intelligent agricultural management, and the method comprises the steps: obtaining soil environment parameters and biological mulching film degradation parameters of the farmland under the biological mulching film coverage condition, and obtaining the relation between biological mulching film degradation products according to the soil environment parameters of the farmland. And based on a geochemical model, inputting a relationship between biological mulching film degradation products and biological mulching film degradation parameters, establishing a farmland greenhouse gas emission amount estimation model under the condition of dynamic degradation of the biological mulching film, and estimating the total greenhouse gas emission amount of the farmland covered by the biological mulching film. The method can accurately estimate the greenhouse gas emission amount of the biofilm mulching farmland, and is beneficial to promoting the development of green and sustainable agriculture.

Description

Technical Field

[0001] The present invention belongs to the field of smart agricultural management, and specifically relates to a method for estimating greenhouse gas emissions from farmland covered with biological mulch. Background Art

[0002] Film mulching technology can significantly increase ground temperature, effectively reduce soil moisture evaporation, increase crop yields and inhibit weeds, and is widely used in agricultural production activities. However, since the main component of ordinary mulch is polyethylene, it is difficult to degrade under natural conditions. With its long-term and large-scale use, the residual film will enter the soil, reduce the air permeability of the tillage layer, hinder the absorption of water and nutrients by crops, and affect the quality of mechanized farming, becoming a prominent problem affecting the sustainable development of agriculture. The promotion of safe and alternative products is an urgent problem to be solved in the development of green agriculture.

[0003] In recent years, my country has increased the research and promotion of biofilm, and biofilm will be used in large quantities in the future. Biofilm is composed of degradable substances such as starch. It is close to plastic film in terms of heat preservation, moisture retention and yield increase effects. It is regarded as a substitute for ordinary film and is gradually accepted by the majority of users. With the wide application, the products of the degradation process of biofilm are crucial to the development of green agriculture and the research on the collection, utilization and treatment system of agricultural waste. However, the impact of biofilm on farmland during the decomposition process and the amount of greenhouse gas produced by farmland when the biofilm no longer has the ability to keep warm and retain moisture in the later stage of the degradation process are still unclear. At present, there are few methods for estimating greenhouse gas emissions from farmland under the conditions of biofilm degradation. Therefore, it is urgent to invent a method for estimating greenhouse gas emission fluxes from farmland under the conditions of biofilm coverage. It is beneficial to my country's future food security, the prevention and control of rural non-point source pollution and the development of green agriculture, and it is also beneficial to the estimation of global greenhouse gas emissions. Summary of the invention

[0004] In order to solve the problem of low estimation accuracy of greenhouse gas emissions from farmland under the condition of dynamic degradation of biological mulch, the present invention provides a method for estimating greenhouse gas emissions from farmland covered with biological mulch.

[0005] In order to achieve the above object, the present invention provides the following technical solution, a method for estimating greenhouse gas emissions from farmland covered with biological mulch, comprising the following steps:

[0006] Obtain historical soil environmental parameters of farmland under biofilm mulching conditions and biofilm degradation parameters;

[0007] According to the soil environmental parameters of the farmland, polynomial fitting is performed on the biofilm degradation products to obtain the relationship between the biofilm degradation products;

[0008] The relationship between the biofilm degradation parameters and the biofilm degradation products is input into the denitrification-decomposition DNDC model to modify the model, thereby obtaining a farmland greenhouse gas emission estimation model that takes into account the dynamic degradation of the biofilm;

[0009] The parameters of the farmland covered with biological mulch to be tested are input into the farmland greenhouse gas emission estimation model to obtain the estimated total amount of various greenhouse gases generated by the farmland under the condition of biological mulch coverage.

[0010] Preferably, the biofilm degradation parameters specifically include: biofilm degradation rate and biofilm degradation area.

[0011] Preferably, obtaining the biofilm degradation area specifically comprises the following steps:

[0012] Continuously acquire images of biofilm degradation and damage in farmland;

[0013] The images of biofilm degradation and damage process were processed by using automated image recognition technology, the images were converted into grayscale images, and the grayscale images were binarized using the adaptive threshold method to find the contour of the biofilm and obtain a binary image.

[0014] The area of ​​degraded biofilm in the farmland is obtained based on the binary image.

[0015] Preferably, obtaining the biofilm degradation rate specifically comprises the following steps:

[0016] Get the degradation time per unit area of ​​biological mulch:

[0017]

[0018] Where A is the area of ​​the biofilm, which depends on f (cm); f (cm) is the particle load of the biofilm; d dry is the thickness of dry biofilm;

[0019] The degradation rate v of the biofilm is obtained based on the area of ​​degraded biofilm in the farmland and the degradation time per unit area of ​​the biofilm:

[0020]

[0021] Where S is the biofilm degradation area.

[0022] Preferably, according to the soil environmental parameters of the farmland, polynomial fitting is performed on the biofilm degradation products to obtain the relationship between the biofilm degradation products. Specifically, the C element and the H element in the biofilm are tracked by using isotope tracking technology to determine the CO2, H20, and SOC generated during the biofilm degradation process. The biofilm degradation products are fitted by polynomial fitting method to obtain the relationship between the three. The relationship between the biofilm degradation products is specifically:

[0023] MCO2=αC M ;

[0024] MSOC=βC M ;

[0025] MH2O=γH M ;

[0026] Wherein, ɑ, β, and γ are proportional coefficients, which are determined according to different soil moisture content, different weather conditions, and different temperatures; MCO2 is the CO2 produced during the degradation of biological mulch per unit time; MH2O is the H2O produced during the degradation of biological mulch per unit time; MSOC is the SOC produced during the degradation of biological mulch per unit time; C M is the carbon (C) content in the biofilm; H M It is the content of hydrogen (H) in the biofilm.

[0027] Preferably, the farmland greenhouse gas emission estimation model specifically includes a decomposition sub-model, a nitrification sub-model and a denitrification sub-model;

[0028] Obtaining greenhouse gas emissions from biofilm-covered farmland through the decomposition sub-model includes the following steps:

[0029] Time t and rate v of biofilm degradation and soil organic matter decomposition M Affected by water content, temperature and O2 concentration, it is calculated by the following formula:

[0030]

[0031] v M =μ CLAY ×μ CN ×μ tm ×(S×K1+(1-S)K r +tids·MSOC);

[0032] R M =R C +tids·MSOC+tids·MCO2;

[0033]

[0034] Where, t M is the sum of the decomposition time of biofilm carbon and soil carbon pool carbon; R M The amount of soil organic matter and carbon dioxide produced by the degradation of biofilm and the total amount of decomposition residues; M is the total decomposition rate of biofilm carbon and soil carbon pool; μ CLAY is the clay content reduction factor; μ CN is the C:N reduction rate; μ tm is the composite cooling and dehumidification coefficient; S is the unstable component of organic compounds in the reservoir; K1 is the decomposition rate of the unstable component; K r is the resistance fraction of the decomposition rate of the unstable component; R C is the total decomposition residue; B is the total amount of denitrifying organisms; eff is the efficiency of microbial decomposition of residues; COP is the CO2 during the decomposition of residues;

[0035] The following steps are involved in obtaining greenhouse gas emissions from farmland under biofilm mulch conditions using the nitrification model:

[0036] N2O release calculation formula:

[0037] N2O (M) =(0.0014·σNO4 / 30)·(0.54+0.51·τT) / 15.8;

[0038] N2O (B) =(0.0014·NO4 / 30)·(0.54+0.51·T) / 15.8;

[0039] In the formula, N2O (M) is the N2O emission under the condition of biofilm covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; σ is the NH4 + The concentration increase coefficient of NH4 is the concentration of NH4 in the soil liquid. + concentration; τ is the reduction coefficient of soil temperature after the biofilm is damaged; T is the soil temperature;

[0040] The following steps are involved in obtaining greenhouse gas emissions from farmland under biofilm mulch conditions using the denitrification sub-model:

[0041] CO2 production:

[0042]

[0043] Production of N2 and N2O:

[0044] N 2(M)=0.17+(0.025-0.013AD·ζPA);

[0045] N2O (M) =(0.0006+0.0013·AD)+(0.013-0.005AD)·ζPA;

[0046] N 2(B) =0.17+(0.025-0.013AD·PA);

[0047] N2O (B) =(0.0006+0.0013·AD)+(0.013-0.005AD)·PA;

[0048] CH4 emissions:

[0049] CH 4(M) =kCH4·Chet·f(T m )·f(θ m )·f(O2);

[0050] CH 4(B) =kCH4·Chet·f(T B )·f(θ B )·f(O2);

[0051] In the formula, CO 2(M) CO is the CO2 produced during denitrification under biofilm covering conditions; CO 2(B) is the CO2 produced during denitrification under unfilmed conditions; k is the inhibition coefficient of the potential growth rate of denitrifying bacteria after denitrification is inhibited; is the potential growth rate of denitrifying bacteria; Ccon is the consumable soluble C; Ccon,t is the total amount of consumable soluble C; AD is the adsorption coefficient, which depends on the clay content in the soil and ranges from 0 to 2; PA is the aeration fraction of the total porosity; ζ is the increase coefficient of the total porosity of the soil after the biofilm is degraded; N 2(M) is the intermediate N2 produced by the soil under the condition of biological film covering; N 2(B) It is the intermediate N2 produced by farmland soil under unmulched conditions; N2O (M) N2O is the N2O produced in the soil under the condition of biological film covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; kCH4 is the intrinsic rate constant of methane production rate; Chet is the concentration of decomposable heterotrophic organic carbon in the soil; f(T) is the influence factor of temperature on methane production rate; f(θ) is the influence factor of soil moisture on methane production rate; f(O2) is the influence factor of oxygen concentration on methane production rate; M is biological mulch covering; B is bare land.

[0052] Preferably, the soil environmental parameters of the farmland specifically include soil moisture content, meteorological data, soil temperature and soil organic matter content.

[0053] The present invention also provides a system for estimating greenhouse gas emissions from farmland covered with biological mulch film, which specifically includes:

[0054] The parameter acquisition module is used to obtain soil environmental parameters of farmland under biofilm covering conditions and biofilm degradation parameters.

[0055] The degradation relationship module is used to perform polynomial fitting on the biofilm degradation products according to the soil environmental parameters of the farmland to obtain the relationship between the biofilm degradation products.

[0056] The model module is used to input the relationship between the biofilm degradation parameters and the biofilm degradation products into the denitrification-decomposition DNDC model to modify the model, so as to obtain a farmland greenhouse gas emission estimation model considering the dynamic degradation of the biofilm.

[0057] The emission module is used to input the parameters of the farmland covered with biological film to be detected into the farmland greenhouse gas emission estimation model to obtain the estimated total amount of various greenhouse gases generated by the farmland under the condition of biological film coverage.

[0058] The present invention also provides a computer device, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement any step in the method for estimating greenhouse gas emissions from farmland covered with biological mulch.

[0059] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is loaded by a processor, it can execute any step of the method for estimating greenhouse gas emissions from farmland covered with biological mulch.

[0060] The method for estimating greenhouse gas emissions from farmland covered with biological mulch provided by the present invention has the following beneficial effects:

[0061] The present invention calculates the relationship between biofilm degradation products through the acquired farmland environmental parameters, obtains the relationship between biofilm degradation products under different environmental influence conditions, provides more accurate data for model estimation, and corrects the denitrification-decomposition DNDC model according to the acquired biofilm degradation parameters and the relationship between biofilm degradation products, establishes a farmland greenhouse gas emission estimation model based on the dynamic degradation of biofilm, obtains the total amount of greenhouse gases generated by farmland under the condition of biofilm coverage, improves the monitoring accuracy of greenhouse gas emissions under the condition of biofilm coverage, and estimates the total amount of greenhouse gas emissions more accurately. It provides basic data for subsequent farmland research, assists in the prevention and control of rural non-point source pollution, and develops green agriculture and other related research. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 The present invention is a flow chart of a method for estimating greenhouse gas emissions from farmland covered with biological mulch.

[0064] Figure 2 This is a technical roadmap for a method for estimating greenhouse gas emissions from farmland covered with biological mulch according to Example 1 of the present invention.

[0065] Figure 3 This is a diagram of an automatic device for collecting greenhouse gases from farmland in an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0067] Example 1

[0068] The present invention provides a method for estimating greenhouse gas emissions from farmland covered with biological mulch. The technical roadmap is as follows: Figure 2 As shown, the specific steps include:

[0069] S1. Parameter collection of farmland under biological mulch covering conditions.

[0070] (1) Soil moisture content: In the 0-20cm soil layer of the farmland covered with biological mulch, a real-time soil moisture monitoring system is pre-buried, and the real-time transmission of monitoring data is achieved through its wireless module, and the soil moisture data is processed through the data processing terminal. The monitoring equipment consists of a soil moisture sensor, a wireless transmission module, a data recording and processing module, and a solar battery.

[0071] (2) Meteorological data: A fully automatic meteorological monitoring system is set up in an open area 500m away from the farmland. The wireless module can transmit the monitoring data in real time and the data processing terminal can process the meteorological data. The fully automatic meteorological monitoring system consists of soil water and heat sensors, meteorological parameter sensors, wireless transmission modules and solar batteries.

[0072] (3) The damaged area of ​​ground film is measured by using a ground film damage rate monitoring system installed 20 cm above the ground film. The ground film damage is photographed at predetermined time intervals, and the relevant images are uploaded to the data processing terminal. The ground film damage area is calculated using image automatic recognition and processing technology. The monitoring system consists of high-definition camera monitoring, wireless transmission module, image and data processing module, and solar battery.

[0073] (4) Soil organic matter content: Through the wireless soil organic matter detection and collection system deployed in the farmland, the soil organic matter content data of the 0-20cm soil layer of the farmland is continuously obtained. The collection system consists of a soil organic matter detector, a data recording and processing module, a wireless transmission module and a solar battery.

[0074] (5) Soil temperature: The soil temperature wireless monitoring and collection system deployed in the farmland can continuously obtain the soil temperature data of the 0-20cm soil layer in the farmland in real time. The monitoring system consists of a soil temperature sensor, a data recording and processing module, a wireless transmission module and a solar battery.

[0075] S2. Establish a database.

[0076] (1) Crop parameter database. Crop growth parameter database and crop types, including plant height and leaf area of ​​major crops in different climate zones, the most suitable temperature for crop growth, maximum temperature, maximum yield, minimum yield, and the most suitable amount of fertilizer.

[0077] (2) Soil parameter database: longitude and latitude, soil stratification, organic matter content, field water holding capacity, wilting coefficient, pH value, etc.

[0078] (3) Meteorological parameter database. Maximum temperature, minimum temperature, rainfall, solar radiation, wind speed, relative humidity. Meteorological data comes from the fully automatic meteorological monitoring system 500m away from the farmland and the China Meteorological Data Sharing Network.

[0079] (4) Field management measures database: data on fertilization, irrigation, drainage, etc.

[0080] S3. The collected parameter data are connected to a database to automatically calculate the biofilm degradation time and biofilm degradation rate.

[0081] 1) Biofilm degradation time per unit area:

[0082]

[0083] Where A is the area of ​​the biofilm, which depends on f (cm); f (cm) is the particle load of the biofilm; d dry is the thickness of dry biofilm.

[0084] 2) Biofilm degradation rate v:

[0085]

[0086] Where S is the biofilm degradation area.

[0087] S4. Based on environmental parameters and the decomposition principle of carbon and oxygen substances, determine the relationship between the three biofilm degradation products CO2, H20 and SOC.

[0088] The degradation products of biofilm include CO2, H20, and SOC. Affected by different weather, soil, and water content, the relationship between the three is also different. Polynomial Fit is used to fit the degradation products of biofilm. Combined with isotope tracking technology, the C and H elements in the biofilm are tracked to determine the CO2, H20, and SOC produced during the degradation of the biofilm, and the relationship between the three is obtained:

[0089] MCO2=αC M ;

[0090] MSOC=βC M ;

[0091] MH2O=γH M ;

[0092] Wherein, ɑ, β, and γ are proportional coefficients, which are determined according to different soil moisture content, different weather conditions, and different temperatures; MCO2 is the CO2 produced during the degradation of biological mulch per unit time; MH2O is the H2O produced during the degradation of biological mulch per unit time; MSOC is the SOC produced during the degradation of biological mulch per unit time; C M is the carbon content in the biofilm; H M It is the content of hydrogen in biological mulch.

[0093] S5. Based on the geochemical model and the relationship between biofilm degradation parameters and biofilm degradation products, a greenhouse gas emission estimation model for farmland under the dynamic degradation conditions of biofilm is established.

[0094] (1) Decomposition sub-model:

[0095] Time t and rate v of biofilm degradation and soil organic matter decomposition M Affected by moisture content, temperature and O2 concentration.

[0096]

[0097] v M =μ CLAY ×μ CN ×μ tm ×(S×K1+(1-S)K r +tids·MSOC);

[0098] R M =R C +tids·MSOC+tids·MCO2;

[0099]

[0100] Where, t M is the sum of the decomposition time of biofilm carbon and soil carbon pool carbon; R M The amount of soil organic matter and carbon dioxide produced by the degradation of biofilm and the total amount of decomposition residues; M is the total decomposition rate of biofilm carbon and soil carbon pool; μ CLAY is the clay content reduction factor; μ CN is the C:N reduction rate; μ tm is the composite cooling and dehumidification coefficient; S is the unstable component of organic compounds in the reservoir; K1 is the decomposition rate of the unstable component; K r is the resistance fraction of the decomposition rate of the unstable component; R C is the total decomposition residue; B is the total amount of denitrifying organisms; eff is the efficiency of microbial decomposition of residues; COP is the CO2 during the decomposition of residues.

[0101] (2) Nitration model:

[0102] Nitrification is affected by the biofilm degradation rate v; when the biofilm degradation rate is fast, the oxygen content (O2) entering the soil increases, nitrification is promoted, and NO3 in the soil liquid - When the biofilm is damaged, the thermal insulation effect of the film is weakened and the soil temperature fluctuation increases;

[0103] N2O release calculation formula:

[0104] N2O (M) =(0.0014·σNO4 / 30)·(0.54+0.51·τT) / 15.8;

[0105] N2O (B) =(0.0014·NO4 / 30)·(0.54+0.51·T) / 15.8;

[0106] In the formula, N2O (M) is the N2O emission under the condition of biofilm covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; σ is the NH4 + The concentration increase coefficient of NH4 is the concentration increase coefficient of NH4 in soil liquid. + concentration; τ is the reduction coefficient of soil temperature after the biofilm is damaged; T is the soil temperature.

[0107] (3) Denitrification sub-model:

[0108] Denitrification is affected by the biofilm degradation rate v; during the biofilm degradation process, the O2 concentration in the soil increases and denitrification is inhibited.

[0109] CO2 production:

[0110]

[0111] Production of N2 and N2O:

[0112] N 2(M) =0.17+(0.025-0.013AD·ζPA);

[0113] N2O (M) =(0.0006+0.0013·AD)+(0.013-0.005AD)·ζPA;

[0114] N 2(B) =0.17+(0.025-0.013AD·PA);

[0115] N2O (B) =(0.0006+0.0013·AD)+(0.013-0.005AD)·PA;

[0116] CH4 emissions:

[0117] CH 4(M) =kCH4·Chet·f(T m )·f(θ m)·f(O2);

[0118] CH 4(B) =kCH4·Chet·f(T B )·f(θ B )·f(O2);

[0119] In the formula, CO 2(M) CO is the CO2 produced during denitrification under biofilm covering conditions; CO 2(B) is the CO2 produced during denitrification under unfilmed conditions; k is the inhibition coefficient of the potential growth rate of denitrifying bacteria after denitrification is inhibited; is the potential growth rate of denitrifying bacteria; Ccon is the consumable soluble C; Ccon,t is the total amount of consumable soluble C; AD is the adsorption coefficient, which depends on the clay content in the soil and ranges from 0 to 2; PA is the aeration fraction of the total porosity; ζ is the increase coefficient of the total porosity of the soil after the biofilm is degraded; N 2(M) is the intermediate N2 produced by the soil under the condition of biological film covering; N 2(B) It is the intermediate N2 produced by farmland soil under unmulched conditions; N2O (M) N2O is the N2O produced in the soil under the condition of biological film covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; kCH4 is the intrinsic rate constant of methane production rate; Chet is the concentration of decomposable heterotrophic organic carbon in the soil; f(T) is the influence factor of temperature on methane production rate; f(θ) is the influence factor of soil moisture on methane production rate; f(O2) is the influence factor of oxygen concentration on methane production rate; M is biological mulch covering; B is bare land.

[0120] The present invention also provides a device for automatically collecting greenhouse gases from farmland soil. Figure 3 As shown, it includes: a collection bottle, a collection bucket with a base, a ventilation device, a data recorder, a gas flow meter, a solenoid valve, and a magnetic suction device. By remotely controlling the opening and closing of the solenoid valve and the magnetic suction device, the soil greenhouse gas is fully automatically collected to verify the accuracy of the greenhouse gas estimation method proposed in the present invention.

[0121] The advantages of the method for estimating greenhouse gas emissions from farmland under biofilm coverage conditions of the present invention are: (1) a high-definition infrared camera biofilm damage monitoring system is installed at a vertical height of 20 cm from the biofilm to continuously monitor the degradation and damage of the biofilm in real time, and the biofilm degradation area is determined using automated image recognition technology; (2) biofilm degradation rate and damage rate factors are introduced to establish a greenhouse gas emission estimation model for farmland under dynamic degradation conditions of biofilm, and the CO2, N2O, and CH4 emissions from farmland covered with biofilm are accurately predicted.

[0122] Example 2

[0123] Field experiments were conducted at the Jiuzhuang Water-Saving Comprehensive Experimental Station (107°18′E, 40°41′N) in Shuanghe Town, Hetao Irrigation District, Inner Mongolia from 2019 to 2020. The experimental station has a typical mid-temperate semi-arid continental climate, with an average annual precipitation of 138.8 mm, an average annual temperature of 6.8°C, a large temperature difference between day and night, and a sunshine time of up to 3230 h. It is one of the regions with the longest sunshine hours in China. The experimental area is mainly composed of silt loam, and the soil bulk density of 0-100 cm is 1.42 g cm -3 The field water holding capacity, effective soil moisture content and soil moisture content at wilting point were 0.36, 0.29 and 0.12 cm, respectively. 3 cm -3 The total nitrogen, total phosphorus and total potassium contents (mass ratio) in the soil were 0.1%, 0.08% and 1.7% respectively, the mass ratio of organic matter was 1.2%, and the pH value was 7.6.

[0124] The corn sowing time was May 4, 2019 and May 10, 2020, respectively, and the growth period was 140 and 145 days, respectively. The planting method adopted "one film, one tube, two rows", and the test film was a biological film (thickness 0.008mm, width 80cm). The experimental irrigation level was full irrigation, and the number of irrigations in the two years was 9 and 7 times, respectively. The drip irrigation belt used a dripper with a design flow rate of 2.4L h -1 The drip irrigation tape was used with a dripper spacing of 30 cm, and a water meter (accuracy of 0.001) was set to monitor the water volume. The base fertilizer composition mainly included urea, diammonium phosphate and potassium sulfate, of which diammonium phosphate and potassium sulfate were applied at 120 kg ha -1 , urea application rate was 20% of total nitrogen. Urea liquid fertilizer (N: 32%) was used as topdressing, and 20%, 30% and 20% of total nitrogen were applied at the jointing stage, tasseling stage and grain filling stage respectively. Each treatment was repeated 3 times, and the plot was 20m long and 4m wide.

[0125] Comparative Example 1: The greenhouse gas emissions from the biofilm-covered farmland were monitored using a static darkroom-meteorological chromatography analysis method as the measured value;

[0126] In comparative example 2, the DNDC model, CENTURY model and Roth-C model were used to estimate greenhouse gas emissions from farmland covered with biological mulch.

[0127] Table 1 Comparison of simulation accuracy of different greenhouse gas models for farmland covered with degradable mulch

[0128]

[0129]

[0130] As shown in Table 1, the statistical analysis results show that the simulated values ​​of the four farmland greenhouse gas emission estimation models are relatively close to the measured values, among which the estimation accuracy of the proposed method is the highest, and the statistical parameter determination coefficient (R 2 ), the mean relative error (MRE) and consistency index (IA) are 0.85-0.88, 9.6%-9.8% and 0.95-0.97 respectively. In general, the estimation accuracy of the present invention is improved by 16.7% compared with the existing method.

[0131] The present invention also provides a system for estimating greenhouse gas emissions from farmland covered with biological mulch film, which specifically includes:

[0132] The parameter acquisition module is used to obtain soil environmental parameters of farmland under biofilm covering conditions and biofilm degradation parameters.

[0133] The degradation relationship module is used to perform polynomial fitting on the biofilm degradation products according to the soil environmental parameters of the farmland to obtain the relationship between the biofilm degradation products.

[0134] The model module is used to input the relationship between biofilm degradation parameters and biofilm degradation products into the denitrification-decomposition DNDC model to modify the model and obtain a farmland greenhouse gas emission estimation model considering the dynamic degradation of biofilm.

[0135] The emission module is used to input the parameters of the farmland covered with biological mulch to be tested into the farmland greenhouse gas emission estimation model to obtain the estimated total amount of various greenhouse gases generated by the farmland under the condition of biological mulch coverage.

[0136] Each module in the above-mentioned system for estimating greenhouse gas emissions from farmland under the condition of biofilm mulch coverage can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the above modules.

[0137] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps in an embodiment of a method for estimating greenhouse gas emissions from farmland under biological mulch covering conditions. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0138] Furthermore, the present invention also provides a non-temporary computer-readable storage medium containing instructions, and a computer program is stored on the storage medium. For example, a memory containing instructions, the above instructions can be executed by a processor of a computer device to complete the above method. For example, a non-temporary computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc. When the computer program is executed by the processor, it can implement the steps in an embodiment of a method for estimating greenhouse gas emissions from farmland under conditions of biological film covering. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0139] It will be appreciated by those skilled in the art that embodiments of the present invention may provide methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0140] The present invention is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as a combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0141] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0142] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0143] It should be pointed out that the specific implementation methods described above can enable those skilled in the art to understand the invention more comprehensively, but do not limit the invention in any way. Therefore, although the invention has been described in detail in this specification and embodiments, those skilled in the art should understand that the invention can still be modified or replaced by equivalents; and all technical solutions and improvements that do not deviate from the spirit and scope of the invention are included in the protection scope of the patent for the invention. Any figure mark in the claims should not be regarded as limiting the claims involved. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belongs to the protection scope of the present invention.

Claims

1. A method for estimating greenhouse gas emissions from farmland covered with biological mulch, characterized in that: The following steps are involved: Obtain historical soil environmental parameters of farmland under biofilm mulching conditions and biofilm degradation parameters; According to the soil environmental parameters of the farmland, polynomial fitting is performed on the biofilm degradation products to obtain the relationship between the biofilm degradation products; The relationship between the biofilm degradation parameters and the biofilm degradation products is input into the denitrification-decomposition DNDC model to modify the model, thereby obtaining a farmland greenhouse gas emission estimation model that takes into account the dynamic degradation of the biofilm; The parameters of the farmland covered with biological mulch to be tested are input into the farmland greenhouse gas emission estimation model to obtain the estimated total amount of various greenhouse gases generated by the farmland under the condition of biological mulch coverage.

2. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 1, characterized in that: The biofilm degradation parameters specifically include: biofilm degradation rate and biofilm degradation area.

3. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 2, characterized in that: Obtaining the biofilm degradation area specifically includes the following steps: Continuously acquire images of biofilm degradation and damage in farmland; The images of biofilm degradation and damage process were processed by using automated image recognition technology, the images were converted into grayscale images, and the grayscale images were binarized using the adaptive threshold method to find the contour of the biofilm and obtain a binary image. The area of ​​degraded biofilm in the farmland is obtained based on the binary image.

4. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 2, characterized in that: Obtaining the biofilm degradation rate specifically comprises the following steps: Get the degradation time per unit area of ​​biological mulch: Where A is the area of ​​the biofilm, which depends on f (cm); f (cm) is the particle load of the biofilm; d dry is the thickness of dry biofilm; The degradation rate v of the biofilm is obtained based on the area of ​​degraded biofilm in the farmland and the degradation time per unit area of ​​the biofilm: Where S is the biofilm degradation area.

5. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 1, characterized in that: According to the soil environmental parameters of the farmland, polynomial fitting is performed on the biofilm degradation products to obtain the relationship between the biofilm degradation products. Specifically, the C element and the H element in the biofilm are tracked by using the isotope tracking technology to determine the CO2, H20, and SOC generated during the biofilm degradation process. The biofilm degradation products are fitted by the polynomial fitting method to obtain the relationship between the three. The relationship between the biofilm degradation products is specifically as follows: MCO2=αC M ; MSOC=βC M ; MH2O=γH M ; Wherein, ɑ, β, and γ are proportional coefficients, which are determined according to different soil moisture content, different weather conditions, and different temperatures; MCO2 is the CO2 produced during the degradation of biological mulch per unit time; MH2O is the H2O produced during the degradation of biological mulch per unit time; MSOC is the SOC produced during the degradation of biological mulch per unit time; C M is the carbon content in the biofilm; H M It is the content of hydrogen in biological mulch.

6. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 1, characterized in that: The farmland greenhouse gas emission estimation model specifically includes a decomposition sub-model, a nitrification sub-model and a denitrification sub-model; Obtaining greenhouse gas emissions from biofilm-covered farmland through the decomposition sub-model includes the following steps: Time t and rate v of biofilm degradation and soil organic matter decomposition M Affected by water content, temperature and O2 concentration, it is calculated by the following formula: v M =μ CLAY ×μ CN ×μ tm ×(S×K1+(1-S)K r +tids·MSOC); R M =R C +time·MSOC+time·MCO2; Where, t M is the sum of the decomposition time of biofilm carbon and soil carbon pool carbon; R M The amount of soil organic matter and carbon dioxide produced by the degradation of biofilm and the total amount of decomposition residues; M is the total decomposition rate of biofilm carbon and soil carbon pool; μ CLAY is the clay content reduction factor; μ CN is the C:N reduction rate; μ tm is the composite cooling and dehumidification coefficient; S is the unstable component of organic compounds in the reservoir; K1 is the decomposition rate of the unstable component; K r is the resistance fraction of the decomposition rate of the unstable component; R C is the total decomposition residue; B is the total amount of denitrifying organisms; eff is the efficiency of microbial decomposition of residues; COP is the CO2 during the decomposition of residues; The following steps are involved in obtaining greenhouse gas emissions from farmland under biofilm mulch conditions using the nitrification model: N2O release calculation formula: N2O (M) =(0.0014·σNO4 / 30)·(0.54+0.51·τT) / 15.8; N2O (B) =(0.0014·NO4 / 30)·(0.54+0.51·T) / 15.8; In the formula, N2O (M) is the N2O emission under the condition of biofilm covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; σ is the NH4 + The concentration increase coefficient of NH4 is the concentration of NH4 in the soil liquid. + concentration; τ is the reduction coefficient of soil temperature after the biofilm is damaged; T is the soil temperature; The following steps are involved in obtaining greenhouse gas emissions from farmland under biofilm mulch conditions using the denitrification sub-model: CO2 production: Production of N2 and N2O: <h2 style=";text-align:left;direction:ltr">N<h2 style=";text-align:left;direction:ltr"> 2(M) <h2 style=";text-align:left;direction:ltr"> =0.17+(0.025-0.013AD·ζPA); N2O (M) =(0.0006+0.0013·AD)+(0.013-0.005AD)·ζPA; <h2 style=";text-align:left;direction:ltr">N<h2 style=";text-align:left;direction:ltr"> 2(B) <h2 style=";text-align:left;direction:ltr"> =0.17+(0.025-0.013AD·PA); <h2 style=";text-align:left;direction:ltr">N2O<h2 style=";text-align:left;direction:ltr"> (B) <h2 style=";text-align:left;direction:ltr"> =(0.0006+0.0013AD)+(0.013-0.005AD)PA; CH4 emissions: CH 4(M) =kCH4·Chet·f(T m )·f(θ m )·f(O2); CH 4(B) =kCH4·Chet·f(T B )·f(θ B )·f(O2); In the formula, CO 2(M) CO is the CO2 produced during denitrification under biofilm covering conditions; CO 2(B) is the CO2 produced during denitrification under unfilmed conditions; k is the inhibition coefficient of the potential growth rate of denitrifying bacteria after denitrification is inhibited; is the potential growth rate of denitrifying bacteria; Ccon is the consumable soluble C; Ccon,t is the total amount of consumable soluble C; AD is the adsorption coefficient, which depends on the clay content in the soil and ranges from 0 to 2; PA is the aeration fraction of the total porosity; ζ is the increase coefficient of the total porosity of the soil after the biofilm is degraded; N 2(M) is the intermediate N2 produced by the soil under the condition of biological film covering; N 2(B) It is the intermediate N2 produced by farmland soil under unmulched conditions; N2O (M) N2O is the N2O produced in the soil under the condition of biological film covering; N2O (B) is the N2O produced in farmland soil under unmulched conditions; kCH4 is the intrinsic rate constant of methane production rate; Chet is the concentration of decomposable heterotrophic organic carbon in the soil; f(T) is the influence factor of temperature on methane production rate; f(θ) is the influence factor of soil moisture on methane production rate; f(O2) is the influence factor of oxygen concentration on methane production rate; M is biological mulch covering; B is bare land.

7. The method for estimating greenhouse gas emissions from farmland covered with biological mulch according to claim 1, characterized in that: The soil environmental parameters of the farmland specifically include soil moisture content, meteorological data, soil temperature and soil organic matter content.

8. A system for estimating greenhouse gas emissions from farmland covered with biological mulch, characterized in that: include: A parameter acquisition module is used to obtain soil environmental parameters of farmland under the condition of biofilm coverage and biofilm degradation parameters; A degradation relationship module, used to perform polynomial fitting on the biofilm degradation products according to the soil environmental parameters of the farmland to obtain the relationship between the biofilm degradation products; A model module, for inputting the relationship between the biofilm degradation parameters and the biofilm degradation products into a denitrification-decomposition DNDC model to modify the model, and obtaining a farmland greenhouse gas emission estimation model considering the dynamic degradation of the biofilm; The emission module is used to input the parameters of the farmland covered with biological film to be detected into the farmland greenhouse gas emission estimation model to obtain the estimated total amount of various greenhouse gases generated by the farmland under the condition of biological film coverage.

9. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is loaded into a processor, it can execute the steps of the method according to any one of claims 1 to 7.

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